import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        
        // 输入一行数据
        String input = scanner.nextLine();
        
        // 使用正则表达式 \\s+ 分割字符串
        String[] words = input.split("\\s+");
        
        // 初始化最长单词和最大长度
        String longestWord = "";
        int maxLength = 0;
        
        // 遍历单词数组，找到最长的单词
        for (String word : words) {
            if (word.length() > maxLength) {
                longestWord = word;
                maxLength = word.length();
            }
        }
        
        // 输出最长单词
        System.out.println(longestWord);
        
        // 关闭scanner对象
        scanner.close();
    }
}